What does the type acronym really means? For many it is no more than another label defining their personalities, just like a star sign. For fewer it has a wider meaning including four Jungian preferences. But how really different are two types with only one letter variation in their acronyms?

Here is a simplified model of the type representing four major aspects:

SpontaneousRealisation

DualSeeking

HiddenAgenda

UnshakableFoundation

Unshakable Foundation - main aspect, this what causes stubbornness in people.
Spontaneous Realisation - when you have an idea, it finds its form of expression here.
Dual Seeking - this defines where you want to be and what you want to see.
Hidden Agenda - has already been explained in here and mentioned in here.

What does an xNTp mean? It's either INTp or ENTp:

INTp

ENTp

As you can see, although they are the same kind of functions (general Intuition, general Sensing ...etc) on the same aspects, the functions are actually inverted (extraverted Intuition vs. introverted Intuition, ...etc). Although the general organisation of the ENTp is similar to INTp, the priorities they give to the same information are different.

The IxTp means INTp or ISTp:

INTp

ISTp

Here both types have similar spontaneous realisations and hidden agendas, but their organisation is fundamentally different and they look for different things.

Next is the INxp type, which is either INTp or INFp:

INTp

INFp

Both types want similar things as their foundation and dual seeking aspects are likewise, however when it comes to realisation, they have different ways of doing it, and they do not share same problem either.